 key “493DE21C824E9541” could not be looked up remotely

To prevent this from happening in the future, you need to update Arch Linux more often, preferably every day. To fix the error, you need to issue the following command as root: sudo pacman -U https://archive.archlinux.org/packages/a/archlinux-keyring/archlinux-keyring-20220927-1-any.pkg.tar.zst